ETgage project, Nebraska Agricultural Water Management Demonstration Network, UNL Extension

Proper staging of your crop is important when estimating crop water use. For example, 4 leaf corn will use much less water than tasseling corn. Crop coefficients (Kc) for nine Nebraska crops based on stage of growth along with descriptions and pictures can be downloaded from this site to help you stage your crop.

The weekly ETgage change value multiplied by your crop stage's crop coefficient (Kc) will give you your crop's estimated water use.

Download Chart (pdf)

Crop Stage	Kc	1.00	1.10	1.20	1.30	1.40	1.50	1.60	1.70	1.80	1.90	2.00	2.10	2.20	2.30	2.40	2.50
Emergence	0.1	0.10	0.11	0.12	0.13	0.14	0.15	0.16	0.17	0.18	0.19	0.20	0.21	0.22	0.23	0.24	0.25
Early Vegetative	0.13	0.13	0.14	0.16	0.17	0.18	0.20	0.21	0.22	0.23	0.25	0.26	0.27	0.29	0.30	0.31	0.33
Vegetative	0.3	0.30	0.33	0.36	0.39	0.42	0.45	0.48	0.51	0.54	0.57	0.60	0.63	0.66	0.69	0.72	0.75
Blossom	0.53	0.53	0.58	0.64	0.69	0.74	0.80	0.85	0.90	0.95	1.01	1.06	1.11	1.17	1.22	1.27	1.33
Early Tuber	0.76	0.76	0.84	0.91	0.99	1.06	1.14	1.22	1.29	1.37	1.44	1.52	1.60	1.67	1.75	1.82	1.90
Tuberization	0.91	0.91	1.00	1.09	1.18	1.27	1.37	1.46	1.55	1.64	1.73	1.82	1.91	2.00	2.09	2.18	2.28
Tuber Bulk	0.85	0.85	0.94	1.02	1.11	1.19	1.28	1.36	1.45	1.53	1.62	1.70	1.79	1.87	1.96	2.04	2.13
Tuber Bulk	0.6	0.60	0.66	0.72	0.78	0.84	0.90	0.96	1.02	1.08	1.14	1.20	1.26	1.32	1.38	1.44	1.50
Senesence	0.3	0.30	0.33	0.36	0.39	0.42	0.45	0.48	0.51	0.54	0.57	0.60	0.63	0.66	0.69	0.72	0.75
Senesence	0.1	0.10	0.11	0.12	0.13	0.14	0.15	0.16	0.17	0.18	0.19	0.20	0.21	0.22	0.23	0.24	0.25
Mature	0.1	0.10	0.11	0.12	0.13	0.14	0.15	0.16	0.17	0.18	0.19	0.20	0.21	0.22	0.23	0.24	0.25

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